De Havilland Heron
Encyclopedia
De Havilland
The de Havilland Aircraft Company was a British aviation manufacturer founded in 1920 when Airco, of which Geoffrey de Havilland had been chief designer, was sold to BSA by the owner George Holt Thomas. De Havilland then set up a company under his name in September of that year at Stag Lane...
DH.114 Heron was a small, propeller
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...
-driven British airliner
Airliner
An airliner is a large fixed-wing aircraft for transporting passengers and cargo. Such aircraft are operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an aircraft intended for carrying multiple passengers in commercial...
that first flew on 10 May 1950. It was a development of the twin-engine de Havilland Dove
De Havilland Dove
The de Havilland DH.104 Dove was a British monoplane short-haul airliner from de Havilland, the successor to the biplane de Havilland Dragon Rapide and was one of Britain's most successful post-war civil designs...
, with a stretched fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
and two more engines. It was designed as a rugged, conventional low-wing monoplane with tricycle undercarriage that could be utilised on regional and commuter routes. One hundred and fifty were built, exported to around 30 countries. Herons later formed the basis for various conversions, such as the Riley Turbo Skyliner and the Saunders ST-27
Saunders ST-27
|-References:NotesBibliography* Gerritsma, Joop. "The Saunders ST-27: A Prop-Jet Commuter Liner by Conversion." Canadian Aviation Historical Society – Journal, Vol. 35, No. 4, Winter 1997....
and ST-28
Saunders ST-27
|-References:NotesBibliography* Gerritsma, Joop. "The Saunders ST-27: A Prop-Jet Commuter Liner by Conversion." Canadian Aviation Historical Society – Journal, Vol. 35, No. 4, Winter 1997....
.
Design and development
Immediately after the Second World WarWorld War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, the aircraft manufacturer de Havilland developed the DH.104 Dove, a small, two-engined passenger aircraft intended as a replacement for the earlier Dragon Rapide
De Havilland Dragon Rapide
The de Havilland DH.89 Dragon Rapide was a British short-haul passenger airliner of the 1930s.-Design and development:Designed by the de Havilland company in late 1933 as a faster and more comfortable successor to the DH.84 Dragon, it was in effect a twin-engined, scaled-down version of the...
, and which soon proved to be successful. As a further development, the company basically enlarged the Dove; the fuselage was lengthened in order to provide room for more passengers or freight, and the wingspan was increased to make room for two additional engines. The Heron was of all-metal construction, and was laid out as a conventional design; the resulting aircraft was able to use many of the parts originally designed for the Dove, thus simplifying logistics for airlines employing both types.
The emphasis was on rugged simplicity in order to produce an economical aircraft for short to medium stage routes in isolated and remote areas which did not possess modern airports. The Heron was designed with a fixed undercarriage and reliable ungeared, unsupercharged Gipsy Queen 30
De Havilland Gipsy Queen
|-Survivors:Of the 11 Gipsy Queen-powered de Havilland Doves on the British register, only two remain airworthy .-Engines on display:Preserved de Havilland Gipsy Queen engines are on public display at the following museums:*de Havilland Aircraft Heritage Centre...
engines.
The Heron prototype registered to the de Havilland Aircraft Company, Hatfield, UK as G-ALZL
Aircraft registration
An aircraft registration is a unique alphanumeric string that identifies a civil aircraft, in similar fashion to a licence plate on an automobile...
undertook its first flight with Geoffrey Pike at the controls on 10 May 1950. The aircraft was unpainted at the time, and after 100 hours of testing, was introduced to the public on 8 September 1950 at the Farnborough Airshow, still glistening in its polished metal state. By November, the prototype had received its formal British Certificate of Airworthiness and had embarked to Khartoum
Khartoum
Khartoum is the capital and largest city of Sudan and of Khartoum State. It is located at the confluence of the White Nile flowing north from Lake Victoria, and the Blue Nile flowing west from Ethiopia. The location where the two Niles meet is known as "al-Mogran"...
and Nairobi
Nairobi
Nairobi is the capital and largest city of Kenya. The city and its surrounding area also forms the Nairobi County. The name "Nairobi" comes from the Maasai phrase Enkare Nyirobi, which translates to "the place of cool waters". However, it is popularly known as the "Green City in the Sun" and is...
for tropical trials.
The prototype was then painted and "prepped" as a company demonstrator, undergoing a trial in 1951 with British European Airways
British European Airways
British European Airways or British European Airways Corporation was a British airline which existed from 1946 until 1974. The airline operated European and North African routes from airports around the United Kingdom...
on their Scottish routes. Following the successful completion of the prototype trials as a regional airliner, the Heron began series production. The first deliveries were to National Airways Corporation
National Airways Corporation
National Airways Corporation was the national domestic airline of New Zealand from 1947 until 1978 when it amalgamated with New Zealand's international airline, Air New Zealand. The airline was headquartered in Wellington...
(NAC, later part of Air New Zealand
Air New Zealand
Air New Zealand Limited is the national airline and flag carrier of New Zealand. Based in Auckland, New Zealand, the airline operates scheduled passenger flights to 26 domestic destinations and 24 international destinations in 15 countries across Asia, Europe, North America and Oceania, and is...
).
Operational service
The first Heron, Series 1A suffered from a number of deficiencies, as NAC soon discovered. First of all, the aircraft was generally underpowered. Its quite heavy engines (weighing approximately 882 lb/400 kg each), had an output of only 250 hp each. By comparison, later modifications or rebuilt aircraft had as much as 50% more power (in the case of the Saunders ST-27). Unlike the Dove, the Heron came with a fixed undercarriage and no nosewheel steering, which simplified maintenance, but reduced top speed.
Very Important Person
A Very Important Person, or VIP is a person who is accorded special privileges due to his or her status or importance.Examples include celebrities, heads of state/heads of government, major employers, high rollers, politicians, high-level corporate officers, wealthy individuals, or any other...
version.
In service, the Heron was generally well-received by flight crews and passengers who appreciated the additional safety factor of the four engines. At a time when smaller airliners were still rare in isolated and remote regions, the DH.114 was able to provide reliable and comfortable service with seating for 17 passengers, in individual seats on either side of the aisle. With its larger fuselage, customers could stand up and large windows were also provided. Baggage was stored in an aft compartment with an additional smaller area in the nose. A few peculiarities cropped up; passengers who filled the aft rows first would find that the Heron gently "sat down" on its rear skid. Pilots and ground crews soon added a tail brace to prevent the aircraft from sitting awkwardly on its tail.
A total of 15 Herons have been operated in Australia since 1952 by carriers such as Butler Air Transport
Butler Air Transport
Butler Air Transport was a limited liability company created by Cecil Arthur Butler to operate air transport primarily among New South Wales airports in Australia, from 1934 until 1959.-History:...
(Tamworth), Connellan Airlines (Alice Springs), Southern Airlines (Melbourne), Kendall Airlines (Wagga Wagga), Heron Airlines (Sydney) and Airlines of Tasmania
Airlines of Tasmania
Airlines of Tasmania, also known by the name Par-Avion, is a small regional airline based in Hobart, Tasmania, Australia. It operates a fleet of light aircraft on scheduled and chartered services between Launceston in Tasmania, Flinders Island and Essendon Airport in Melbourne in Victoria on the...
(Launceston).
Performance throughout the Heron range was "leisurely", and after production ceased in 1963, several companies, most notably Riley Aircraft Corporation, offered various Heron modification "kits," mainly related to replacing the engines, which greatly enhanced takeoff and top speed capabilities. Riley Aircraft replaced the Gipsy Queens with horizontally opposed Lycoming IO-540
Lycoming O-540
|-Specifications :-See also:-External links:...
engines. One airline that carried out conversions was Prinair
Prinair
Prinair was a Puerto Rican airline. It was Puerto Rico's domestic and international flag carrier airline for almost two decades.- History :Services began in 1966, under the name Aerolíneas de Ponce , with Aero Commanders...
, which replaced the Gipsy Queens with Continental
Continental Motors Company
Continental Motors Company was an American engine and automobile manufacturer. The company produced engines for various independent manufacturers of automobiles, tractors, and stationary equipment from the 1900s through the 1960s. Continental Motors also produced Continental-branded automobiles in...
IO-520 engines. Connellan Airways
Connellan Airways
Connellan Airways was an Australian air services company that was founded by Edward Connellan and operated in northern Australia.-The beginnings:...
also converted its Herons, using Riley kits. When available aircraft reached the end of their service lives, the engine conversions gave the elderly airliner a new lease on life as a number of examples were converted in the 1970s and 1980s including N415SA, a Riley Heron still flying in Sweden as of 2011 and a Riley Turbo Skyliner, tail number N600PR currently registered in the United States (this example appeared in the 1986 movie Club Paradise
Club Paradise
Club Paradise is a 1986 American comedy film directed by Harold Ramis starring Robin Williams, Peter O'Toole, and Jimmy Cliff. The film reunites director/co-writer Ramis with most of his SCTV co-stars -- SCTV cast members Andrea Martin, Eugene Levy, Rick Moranis, Joe Flaherty, and Robin Duke play...
).
The most radical modification of the basic Heron airframe was the Saunders ST-27/-28
Saunders ST-27
|-References:NotesBibliography* Gerritsma, Joop. "The Saunders ST-27: A Prop-Jet Commuter Liner by Conversion." Canadian Aviation Historical Society – Journal, Vol. 35, No. 4, Winter 1997....
, that basically changed the configuration as well as the "look" of the whole aircraft with two powerful turboprop
Turboprop
A turboprop engine is a type of turbine engine which drives an aircraft propeller using a reduction gear.The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller...
engines replacing the lethargic four-engine arrangement, the easily recognisable "hump" over the cockpit disappearing, the shape of the windows changed and the wingtips being squared instead of rounded.
Popular culture
The De Havilland Heron is used in the book series Flight 29 DownFlight 29 Down
Flight 29 Down is a television series about a group of teenagers who are stranded on an island. It was produced by Discovery Kids. The show was created by Stan Rogow and D. J. MacHale . The executive producers are Rogow, MacHale, Shauna Shapiro Jackson, and Gina & Rann Watumull...
. A Heron also features in Khufra Run by Jack Higgins
Jack Higgins
Jack Higgins is the principal pseudonym of UK novelist Harry Patterson. Patterson is the author of more than 60 novels. As Higgins, most have been thrillers of various types and, since his breakthrough novel The Eagle Has Landed in 1975, nearly all have been bestsellers...
.
Variants
- Heron 1: Four-engined light transport aircraft. Fitted with fixed landing gear.
- Heron 1B: This model had an increased take-off weight of 13,000 lb (5,897 kg).
- Heron 2: Four-engined light transport aircraft. Fitted with retractable landing gear.
- Heron 2A: This designation was given to a single Heron 2, which was sold to a civil customer in the USA.
- Heron 2B: This model had the same increased takeoff weight as the Heron 1B.
- Heron 2C: Redesignation of the Heron 2Bs, which could be fitted with optional fully feathering propellers.
- Heron 2D: Four-engined light transport aircraft. This model had an increased takeoff weight of 13,500 lb (6,123 kg).
- Heron 2E: VIP transport aircraft. One custom-built aircraft.
- Heron C.Mk 3: VIP transport version for the Queen's Flight, Royal Air ForceRoyal Air ForceThe Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...
(RAF). Two built. - Heron C.Mk 4: VIP transport aircraft for Queen's Flight, RAF. One built.
- Sea Heron C.Mk 20: Transport and communications aircraft for the Royal NavyRoyal NavyThe Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
. Three ex-civil Heron 2s and two Heron 2Bs were acquired by the Royal Navy in 1961. - Riley Turbo Skyliner: Re-engined aircraft. A number of Herons were fitted with 290 hp (216 kW) Lycoming IO-540Lycoming O-540|-Specifications :-See also:-External links:...
flat-six piston engines. The modifications were carried out by the Riley Turbostream Corporation of the USA.
- Saunders ST-27: The fuselage was lengthened by 8 ft 6 in (2.59 m), to accommodate up to 23 passengers. It was powered by two 750 shp (559-kW) Pratt & Whitney Canada PT6Pratt & Whitney Canada PT6The Pratt & Whitney Canada PT6 is one of the most popular turboprop aircraft engines in history, and is produced by Pratt & Whitney Canada. The PT6 family is particularly well known for its extremely high reliability, with MTBO's on the order of 9000 hours in some models. In US military use, they...
A-34 turbopropTurbopropA turboprop engine is a type of turbine engine which drives an aircraft propeller using a reduction gear.The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller...
engines. Twelve Herons were modified by the Saunders Aircraft Corporation of Gimli, ManitobaGimli, ManitobaGimli is a a rural municipality located in the Interlake region of south-central Manitoba, Canada, on the western shore of Lake Winnipeg. It is about north of the provincial capital Winnipeg...
, Canada.- ST-27A and ST-27B : The original designations of the ST-28.
- Saunders ST-28: Improved version of the ST-27. One prototype built.
- Tawron: Conversion by Shin Meiwa of Japan for Toa AirwaysToa AirwaysToa Airways Co., Ltd. was a Japanese airline and the predecessor of Japan Air System.On May 15, 1971, the airline merged with Japan Domestic Airlines to form Toa Domestic Airlines; on April 1, 1988 the merged airline renamed itself to Japan Air System. In the 2000s Japan Air System merged into...
with 260 hp (194 kW) Continental IO-470s replacing the original engines.
Civil operators
Accidents and incidents
- On 18 April 1955, Union Aéromaritime de TransportUnion Aéromaritime de TransportUnion Aéromaritime de Transport was a French airline. It had its head office in the 8th arrondissement of Paris.In addition, on 26 December 1958 a DC-6 of UAT crashed in Salisbury, Rhodesia ....
F-BGOI, crashed into a Kupe Mountain CameroonCameroonCameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...
. 12 out of 14 passengers and crew died in the crash - On 7 november 1956, Braathens SAFE LN-SUR, crash landed in heavy snow on the mountain Hummelfjell in TolgaTolga-Given name:* Tolga Çevik, Turkish actor* Tolga Doğantez, Turkish footballer* Tolga Örnek, Turkish film director* Tolga Seyhan, Turkish footballer* Tolga Zengin, Turkish footballer-Places:* Tolga, Algeria* Tolga, Norway* Tolga, Queensland in Australia...
, NorwayNorwayNorway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
. The pilot and one passenger were killed, whilst the remaining crew and passengers survived. The Hummelfjell accidentHummelfjell AccidentThe Hummelfjell Accident occurred on 7 November 1956 at 9:50, when a de Havilland Heron crashed into the mountain Hummelfjell in Tolga, Norway. The Braathens SAFE aircraft was on route from Trondheim Airport, Værnes to Oslo Airport, Fornebu. The accident was caused by the aircraft losing altitude...
was Braathens SAFE's first fatal accident. - On 28 September 1957, British European AirwaysBritish European AirwaysBritish European Airways or British European Airways Corporation was a British airline which existed from 1946 until 1974. The airline operated European and North African routes from airports around the United Kingdom...
G-AOFY, on an air ambulance flight, crashed on approach to Glenegedale Airport, IslayIslay-Prehistory:The earliest settlers on Islay were nomadic hunter-gatherers who arrived during the Mesolithic period after the retreat of the Pleistocene ice caps. In 1993 a flint arrowhead was found in a field near Bridgend dating from 10,800 BC, the earliest evidence of a human presence found so far...
, in bad weather. The three occupants, two crew and one nurse, were killed. - On 14 April 1958, AviacoAviacoAviación y Comercio, S.A., was a Spanish airline incorporated on February 18, 1948. It was founded when the National Institute of Industry proposed that the national carrier of Spain, Iberia, could not meet the domestic demand. This had been caused by the heavy commitment of Iberia to the lucrative...
EC-ANJ, crashed into the sea off the coast of BarcelonaBarcelonaBarcelona is the second largest city in Spain after Madrid, and the capital of Catalonia, with a population of 1,621,537 within its administrative limits on a land area of...
SpainSpainSpain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
all 16 passengers and crew were killed in the crash. - On 14 October 1960, Itavia I-AOMU crashed on Mount CapanneMount CapanneMount Capanne is the highest mountain on the Italian island of Elba and the province of Livorno. Located in the western part of the island, it reaches a height of 1,019 metres above sea level....
, ItalyItalyItaly , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
killing all 11 on board. - On 17 August 1963, Fujita AirlinesFujita Airlineswas an airline in Japan, formerly known as Nippon Yuran Airlines. The airline operated various types of propeller aircraft, including the Cessna 170, de Havilland Dove and Fokker F27....
JA6159 crashed just after take off into Mount Hachijō-Fuji, HachijōjimaHachijojimais a volcanic Japanese island in the Philippine Sea, administered by Tōkyō and located approximately south of the Special Wards of Tōkyō. It is the southernmost and most isolated of the Izu Seven Islands group of the seven northern islands of the Izu archipelago...
, JapanJapanJapan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
; the accident killed all 19 passengers and crew in the worst disaster suffered by the de Havilland Heron. - On 27 January 1968, Air Comoros F-OCED flight hit the runway at MoroniMoroni, Comoros-References:...
, ComorosComorosThe Comoros , officially the Union of the Comoros is an archipelago island nation in the Indian Ocean, located off the eastern coast of Africa, on the northern end of the Mozambique Channel, between northeastern Mozambique and northwestern Madagascar...
and overran the runway then crashed into the sea. 15 passenger and crew died but 1 person survived the accident. - On 24 June 1972, Prinair Flight 191Prinair Flight 191Prinair Flight 191 was a Prinair flight from Luis Muñoz Marín International Airport in San Juan, Puerto Rico, to Mercedita Airport in Ponce, Puerto Rico. At approximately 11:15pm on 24 June 1972, the aircraft crashed while attempting to land at Mercedita Airport...
crashed near PoncePonce, Puerto RicoPonce is both a city and a municipality in the southern part of Puerto Rico. The city is the seat of the municipal government.The city of Ponce, the fourth most populated in Puerto Rico, and the most populated outside of the San Juan metropolitan area, is named for Juan Ponce de León y Loayza, the...
, Puerto RicoPuerto RicoPuerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
killing five people out of 20 passengers and crew.